Observations of defect structure evolution in proton and Ni ion irradiated Ni-Cr binary alloys

Samuel Briggs, Christopher Barr, Janne Pakarinen, Mahmood Mamivand, Khalid Hattar, Dane Morgan, Mitra Taheri, Todd Allen

    Research outputpeer-review

    Abstract

    Two binary Ni-Cr model alloys with 5 wt.% Cr and 18 wt.% Cr were irradiated using 2 MeV protons at 400 and 500 °C and 20 MeV Ni4+ ions at 500 °C to investigate microstructural evolution as a function of composition, irradiation temperature, and irradiating ion species. Transmission electron microscopy (TEM) was applied to study irradiation-induced void and faulted Frank loops microstructures. Irradiations at 500 °C were shown to generate decreased densities of larger defects, likely due to increased barriers to defect nucleation as compared to 400 °C irradiations. Heavy ion irradiation resulted in a larger density of smaller voids when compared to proton irradiations, indicating in-cascade clustering of point defects. Cluster dynamics simulations were in good agreement with the experimental findings, suggesting that increases in Cr content lead to an increase in interstitial binding energy, leading to higher densities of smaller dislocation loops in the Ni-18Cr alloy as compared to the Ni-5Cr alloy.
    Original languageEnglish
    Pages (from-to)48-58
    Number of pages10
    JournalJournal of Nuclear Materials
    VolumeOctober 2016
    DOIs
    StatePublished - 27 Jun 2016

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